Significance

Wind speeds over open ocean areas are often higher than those in the windiest areas over land, which has motivated a quest
to develop technologies that could harvest wind energy in deep water environments. However, it remains unclear whether these
open ocean wind speeds are higher because of lack of surface drag or whether a greater downward transport of kinetic energy
may be sustained in open ocean environments. Focusing on the North Atlantic region, we provide evidence that there is potential
for greater downward transport of kinetic energy in the overlying atmosphere. As a result, wind power generation over some
ocean areas can exceed power generation on land by a factor of three or more.

Abstract

Wind turbines continuously remove kinetic energy from the lower troposphere, thereby reducing the wind speed near hub height.
The rate of electricity generation in large wind farms containing multiple wind arrays is, therefore, constrained by the rate
of kinetic energy replenishment from the atmosphere above. In recent years, a growing body of research argues that the rate
of generated power is limited to around 1.5 W m?2 within large wind farms. However, in this study, we show that considerably higher power generation rates may be sustainable
over some open ocean areas. In particular, the North Atlantic is identified as a region where the downward transport of kinetic
energy may sustain extraction rates of 6 W m?2 and above over large areas in the annual mean. Furthermore, our results indicate that the surface heat flux from the oceans
to the atmosphere may play an important role in creating regions where sustained high rates of downward transport of kinetic
energy and thus, high rates of kinetic energy extraction may be geophysical possible. While no commercial-scale deep water
wind farms yet exist, our results suggest that such technologies, if they became technically and economically feasible, could
potentially provide civilization-scale power.